


Slow Burn

by Aya_A_Anderson



Series: in this castle [1]
Category: Voltron: Legendary Defender
Genre: Alpha/Beta/Omega Dynamics, BDSM, Dom/sub, Galra Keith (Voltron), M/M, Non-Traditional Alpha/Beta/Omega Dynamics, Soulmates, slowburn romance
Language: English
Status: Completed
Published: 2016-08-07
Updated: 2016-08-07
Packaged: 2018-07-29 21:04:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,124
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7699303
Author URL: https://archiveofourown.org/users/Aya_A_Anderson/pseuds/Aya_A_Anderson
Summary: <blockquote class="userstuff">
              <p>Turns out Keith's Galran biology runs more than skin-deep. Lance is afraid. Shiro makes the best of a bad situation.<br/>(Omega!Keith)</p>
            </blockquote>





	Slow Burn

_Shiro couldn’t say he was unprepared for the scent. It was only natural, what with Keith being part-Galran, and Shiro having just recently escaped from a full ship of them. From the year he’d lived in captivity, Shiro had learned to scent out the strong ones, the Galrans who roared for blood, the commanders, the biggest, meanest guards. There were others, most of whom smelled of ordinary sweat from a day’s patrol. The smell reminded Shiro of training, hours of combat classes and nights in the simulators, all home._

_It had taken him months to first notice the difference between sweat and alpha pheromones: the thick, overwhelming scent of a dominant Galran fighter. They were always fighters, guards, figures of authority, as if biologically destined for power. These warriors were bred, not born._

_Shiro had learned to scout for alphas well before they neared him. Their smell would permeate the corridors before them like a warning, and then even the beta guards stood clear. However uncommon alphas were, the scent evoked fear and a willingness to serve Shiro had never seen before; he had learned to be afraid. Locked in his small, dirty room, he couldn’t run, but Shiro believed in the virtues of mental preparation. Strength of mind forged strength of character._

_Still, it was many months after Shiro had become known as Champion before he learned of the alphas’ counterpart. The doctor who regularly accompanied the druids – who may as well be a druid himself for all the empathy he possessed – had been out, and unable to oversee the fifteenth reconstruction of Shiro’s Galra arm._

_Of course, the Galrans rescheduled torture for no man. There had been another sent in his place. It was rare to see any of their kind without a guard’s helmet, especially a Galran woman, but this one was bare-faced and shorter, slighter than the others. She matched Shiro in height, with ears flared larger than Shiro had ever seen them._

_For the rest of the session, Shiro had been distracted, bearing the pain by gritting his teeth and raking through a happy memory, trying to recall every detail. There was only one face he remembered clearly._

_The beautiful woman had smiled at him as she’d left, and Shiro stared after her, not realising his mouth had fallen partway open until one of the regular guards returned to the cell. Not that he was generally so inclined, but the lightness of the woman’s eyes and the sweetness of her smile after months of captivity had seemed to unhinge him. The guard had sniffed the air, and then said a word in the Galran language Shiro didn’t know._

Omega _, he learned. The omegas were too rare to fight as guards, too prized: they bred the alphas, and alpha strength was what the Galrans stood for._

_Their scent was different, and manufactured to arouse and please, distinct and unmistakeable. But that being said, his Paladins were not so well prepared. Galran biology wasn’t a regular topic of conversation in the dining room and Keith, though part-Galran, was as ignorant as the rest of them…_

* * *

 

The week had been oddly peaceful so far – no attacks, betrayals or disappearances for a solid three days – so it was only a matter of time before everything went to hell.

Shiro woke on a natural morning, ship’s east facing a nearby star, to find his cock hard in his pants and the smell of heat in the air. For a minute, he seriously considered handing the burden of leadership off to someone else indefinitely and going back to sleep.

The ceiling was white, lights off, uniform folded at the end of his bed. Everything was as he’d left it the night before. He cautiously inhaled – the room swam, and when he brought his hand to his forehead it came away clammy. The smell was incredible, impossibly strong and sweet, richer and darker than flowers, and strangely familiar. Shiro groaned, feeling the strangest urge to slap himself a few times across the face to wake up. Strangely familiar, he thought, that was odd. It had never been so strong, but it was coming back to him slowly, as if it were part of a half-forgotten dream.

“ _Keith_ ,” he said, and lurched upright in bed. The smell was Keith’s, he knew Keith’s smell – they all smelled disgusting after practice, but when Keith showered there was a slight note of the same rich scent. Gritting his teeth, Shiro held his breath and tugged on his boots, and Keith better not have left his room or so help him, Shiro would –

There was a muffled crash from somewhere in the corridor. 

“Jesus!” came Lance’s voice, “I was just trying to help!”

Keith murmured a reply, voice dangerous and pitched too low for Shiro to hear, but Shiro was already out the door. He stared.

Lance had fallen, or been thrown, and he was staring up at Keith with undisguised fear, and Keith… Keith looked more like a Galran than Shiro had ever seen him. His teeth were bared, and his ears were flared in warning, his stance threatening. 

Shiro had to force himself to re-evaluate: this was Keith, not some Galra soldier. Lance wasn’t trying to fight him off. Keith was still himself.

He took a deep breath, and looked again. Keith’s shoulders were hunched. Though his teeth flashed in fury, his breaths were laboured, and seemed to be curling in on himself as if in pain. Keith was afraid, and he knew even less of what was happening than Shiro did.

“Lance,” said Shiro, softly. “Go to the kitchen. I’ll take care of Keith.”

“Got it,” said Lance, but he didn’t move. He was looking back and forth between them, torn between running and offering to stay and help. Shiro had to smile.

“Go. He’ll be fine.”

Lance shot off after that, all too happy to get away from Keith when he was in a mood like this. Shiro listened to the sound of his footsteps, and knew he would tell the others – Lance was dependable like that, and he’d grown a soft spot for Keith over the months and years they’d spent in space.

He felt a weight against his back.

Keith had slumped, bearing his weight on Shiro – Keith wasn’t heavy, but Shiro turned on instinct to catch him by the shoulders and hold him more gently. He’d known Keith for years, and carrying his weight felt natural. He seemed to trust Shiro more than he trusted Lance – which wasn’t saying much, Shiro thought, since he and Lance had struck up a tentative truce when Keith’s Galran side could no longer be contained.

The team had stuck with Keith, but it was Shiro that he still came to when he wanted someone to listen, or a partner to spar with. Shiro knew he had a duty to the team, but Keith was something else. He’d told himself it was some sense of obligation, that staying close to Keith meant keeping a closer eye on Voltron’s most volatile link, but then Keith would flash him a rare half-smile and Shiro would be forced to re-evaluate himself and everything he stood for, and Shiro would remember the days before Kerberos where they had come so close to resolving whatever it was that hung between them.

“Shiro,” Keith said, and looked up at him, eyes wide and terrified. His normally impassive face was drawn and pale. The scent was overpowering.

“What happened?”

Keith’s shoulders were stiff in Shiro’s hands, strong and lean from training, and Shiro vividly remembered Keith, flat on his back in the training room, flushed with heat.

Keith shook his head, and said “You think I’d be like this if I knew?” then winced, drawing a hand to a spot behind his ear. There, his neck was swollen, burning red against the faint purple of his skin. Keith nearly hissed when Shiro ran a thumb over it – he heard Keith’s breath catch – and Shiro’s thumb came away slick with pheromones.

He stared at it a moment.

“Yeah,” said Keith, sounding disgusted, “that started this morning.”

The smell was strongest there. The scent of pheromone was exhilarating, and driven by an instinct he couldn’t explain, Shiro pressed his lips to the strangely swollen gland and grazed his teeth against it. Scent burst across his tongue in a wave of heat, expelling all thought and reason until all that was left was want, the deep want he always felt when he saw Keith and had to force down deeper. Keith shuddered and bared his neck, the pale arch of it, and Shiro’s hands were pressing the small of Keith’s back deeper into him and moving.

“Shiro,” Keith said again, and there was a hint of urgency in his voice. Shiro jerked back, staring, breath harsh in the corridor’s silence.

“I’m sorry,” he said, “You must be- We should talk about what just happened.”

“Talk,” Keith repeated, and licked his lips. Shiro had never seen him look so totally disarmed, composure lost to the instinct raging through his body, and he didn’t know if it was scent or just the heat that made him seem so beautiful.

Shiro felt suddenly sick, and had to look away.

Keith looked down at the backs of his hands, where his eyes often went when someone, usually Lance, commented on his heritage. Keith was smart, and Shiro knew he would be formulating the right conclusions on his own.

“I guess this is normal for Galrans,” he said bitterly, frowning with all the sharp lines of his face. “As if this couldn’t get any worse.”

Shiro wanted to reach for him, to reassure him the way he would any of them. He stopped, fists clenched at his sides. The way Keith looked, the way they might have been, Shiro didn’t know if he could trust himself not to press his teeth into Keith’s neck and claim him the way that omega had been claimed. Shiro wasn’t meant to suffer from the same compulsions as the Galrans did, let alone their alphas.

He looked down at his own hands, and remembered he wasn’t entirely human, either.

 

* * *

 

 

There had been a time when life had been easier: when Keith and Shiro were pilots and not Paladins, and when Shiro had seen something of himself in Keith and offered to teach him.

Keith had been reluctant at first, but Shiro had been earnest. He’d kept popping up in various places, hoping to surprise Keith into an answer that wasn't an instant _no, stop following me_ , and eventually Keith had given in and agreed to spar with him.

He’d been a new entry to the academy, one step below Garrison level, fifteen and angry at the world. His fighting skills were strange and unmatched by anyone in his class, and Shiro had to push himself to beat him. That was what had first drawn him to Keith: the endless unpredictability of his fighting and his words, the way they seemed to fit together well whether they were sparring or laying on their backs in the aftermath.

“Do you ever think,” Keith started. Then he stopped, and Shiro saw his ears going red in his peripheral vision.

“What?” Shiro prompted, and Keith’s head turned to look at him. His hair was plastered black to his face with sweat, and his eyes were wide and dark. Something inside Shiro fell very fast and settled in a new place in his stomach – Shiro knew what this was, he knew himself, and he’d liked others with something of Keith in them in the past. A girl from his class had the same dry sense of humour, a boy from simulator training had Keith’s eyes – even the boy he’d liked back when Shiro was in school had the same reckless determination, which he’d admired then… Keith was all of these, and more, and Shiro felt something for him.

“Do you ever think about leaving the Garrison?”

Shiro turned to face him. It was strange, laying so close to someone without touching them. Keith seemed to know it, because his arm twitched away from Shiro, but he stayed mostly close and didn’t shut his eyes.

“When I was in the Academy,” said Shiro, slowly, “I thought of leaving. My classmates were competitive before we were sorted into streams. There was a lot of fighting, not just in the ring."

“Yeah. Seems that way.”

“Try not to think on it,” said Shiro. “They’ll calm down when the exams have passed.”

Keith made a small noise of assent, then said nothing else. Shiro watched his breath, the rise and fall of his chest, watched him thinking it over.

Eventually, Shiro said, “Have you decided what you’ll apply for?”

“I want to be a fighter pilot,” said Keith, at once. “They’re sending you on missions, soon. I thought I might want that too.”

Keith was right – even then, Kerberos had been thrown around as a possibility for Shiro, who would soon be graduating. It wasn’t a matter of want; Shiro would go where they sent him, but it helped that he believed in what the Garrison was trying to achieve. He wanted to see the universe, as much of it as he could. It was a dream many could claim, but few had the opportunity to realise, as Shiro did. Shiro looked at Keith and knew he could pilot, knew he would love flying for the thrill, just as Shiro felt his best, his most controlled leading a team. And suddenly, no matter how impossible it was, he wanted Keith up there with him.

“Keep at it,” said Shiro. “You’ll make it into the Garrison. Hell, they’ll be lucky to have you.”

“Sure,” said Keith, rolling his eyes, but he sounded pleased. After a slight pause, he murmured, “Thanks, Shiro.”

Shiro looked at him, and felt the same, odd sensation of falling. “You don’t have to thank me,” he said, and then reached out to brush Keith’s hair with his knuckles, just because it seemed right.

Keith stiffened, and Shiro felt a moment’s panic – Keith was younger than him, junior to him in rank, and seemed to admire him above the others in his class or at the Garrison. And then Shiro had a few more thoughts, but they didn’t matter because Keith was leaning into him, shifting closer to touch Shiro’s knuckles with his forehead, and Shiro felt the air change and hang heavier between them. 

“Shiro,” said Keith, and then he swallowed. Shiro watched the line of his throat shift with it, watched the flush on his face returning in force. “Do you-” 

Shiro heard it just as he did, the sound of footsteps and laughter tracking closer to the gyms, and he realised over again this was an open room, open access to any student or teacher. Keith was faster – he was on his feet before the door opened, already picking up his gym bag from the hardwood floor and nodding to his classmates on his way out. They were looking at Shiro, picking himself up from the floor – they made some comment about Keith on his way out, “ _you think he beat Shiro?” “No way, Shiro’s a tank, they say he’s lined up for the Kerberos mission next year.”_

As sedately as he could with his heart trying to fight its way out through his ribs, Shiro found his own bag and left the room. Then he paused. He looked up and down the long corridor, lights dimmed for the night, and saw no one. Keith would probably have headed back to the student dormitories – Shiro couldn’t lie to himself and say they were close enough for him to follow.

There were other reasons, too, of rank and gossip and all the other pressures someone in Shiro’s position could place on a cadet like Keith. Shiro knew Keith, and knew he could handle himself, but the voice was small in the face of every other new fear Shiro had to consider: all the ways Keith couldn’t be right for him, and then –

Shiro would be leaving soon. Whether it was Kerberos or somewhere else, the mission would be called and he would graduate the program and be sent out, somewhere in the uncharted depths of space, without Keith.

Shiro swallowed, and felt sick at the thought of leaving someone he’d promised something of himself to – he’d heard the older pilots, the instructors talking of their boyfriends, girlfriends, families: everything they had to leave, and never for so long as Shiro would. It wouldn’t be fair to Keith.

And Shiro knew he was projecting too far into an unknown future, because Keith would never have the chance to finish his last sentence. Shiro had his pride and his command: an entire team to look after. And he knew Keith would never say it, but Keith had dreams as big as everyone’s – and Keith was young, and without Shiro’s legacy hanging over his head, he would be better.

 

* * *

 

 

“The room’s free,” said Shiro. His bedroom door was still wide open. “I know what’s happening to you.”

“How?” said Keith, ears flared in warning.

Shiro said his name, and stopped. “I won’t touch you,” he said, holding up his hands. “The Galra on the main craft – some of them were like you.”

Keith had known it before, but Shiro saw the new light come into his eyes as he remembered the time after Kerberos. And Shiro had seen all the small ways Keith had changed since then, knew of the year Keith had spent alone, and knew Keith had every right to be caught up in his own story. 

“I know,” said Keith. “I didn’t forget. I was always thinking about you, up there alone. But-”

“It’s easy to forget the Galra are people, too,” said Shiro.

Keith laughed, breathlessly, and the sound was far from what it had been. What it was, sometimes, on missions. What it was around Lance, when they got on. “Alright. Tell me about weird Galra biology… if that’s what this is.”

Shiro nodded. From Keith’s strained expression, it was taking him a lot of self-control to hold his composure. Shiro could only imagine – wait, he didn’t want to imagine how Keith must be feeling, from the smell and the heat and the dilation of his pupils when he looked at Shiro. Even as Shiro re-entered his room, quickly folding the bedcovers over for Keith to sit on, he could feel Keith watching. 

“There are other Galrans like you,” he said, and told him what he’d seen. As he spoke, he didn’t turn around – he didn’t know if he could meet Keith’s eyes, take another breath of that scent and still refrain from holding him. This wasn’t the garrison: it seemed as if there were lifetimes between then and now, years of distance.

Kieth sat on the bed, his breath rushing out. “And you’re telling me I’m some sort of omega.”

“I think so,” said Shiro. “I can’t be sure, not until Coran runs some tests.”

“How long will this last!?”

He sighed, and turned to face Keith. He looked angry – even more than that, he looked desperate. His panic had let out a small burst of pheromones, and Shiro groaned and had to grit his teeth against it.

“I’ll talk to Allura and Coran,” he promised. “They’ll know more than I do.”

“Don’t-” Keith’s hand shot out to catch his shirt, though he hadn’t even moved. His dark head was bowed, and he was shaking, and Shiro could feel the thin claws through his shirt. “Don’t leave!”

“I’m not leaving,” Shiro reassured him. “If you don’t want me to leave, I’ll stay with you.”

“Don’t leave,” Keith said again.

“I won’t.”

“It hurts, Shiro.”

Keith lifted his head, and Shiro saw the fever that had spread across his cheeks, the unhealthy haze in Keith’s eyes. Keith wasn’t the sort to complain over trivial things and Shiro could feel the heat in Keith’s forehead against his hand, Keith clutching at his shirt.

“I... should get Coran.” But he trailed off, letting Keith hold fast and moving to rest his chin on Keith’s hair. He couldn’t leave now. Keith needed him.

After a few, silent moments, Keith spoke again. “Do you ever think about what would’ve happened? If Kerberos hadn’t been in the picture.”

Shiro just held him tighter.

“I’ve thought about it,” Keith continued, and his fingers clenched tighter. He was trembling, very slightly, and his voice was low. “I had a long time to think about it, even before you left. But I guess I was just a coward.”

“You’re not a coward,” said Shiro, running a thumb over Keith’s neck. “You were fifteen.”

“And you were eighteen,” Keith countered, “and the best pilot in the Garrison. Now, you’re leading Voltron! Next to you, we’re just kids.”

“We are teammates,” Shiro said firmly. “And, Keith – you were never a child. You brought me home.”

“And if I hadn’t, Lance would have!”

“No!” Shiro pulled back, forcing Keith to look at him. His face was the one thing Shiro remembered with clarity; even after his Galran genes had surfaced, Keith’s face had stayed the same, his eyes, his lips, the sharp lines of his jaw. Shiro could look at him forever. 

“After the mission failed,” Shiro said, “We were taken to Zarkon’s ship. I was forced to fight, day after day. Weeks and months passed, but we knew none of it. And after a while, I didn’t know how long it was – whether a day had passed, or years. Half the time, I didn’t even know when I was awake. I’d done my best for humanity, and I’d accepted that I would die there.”

Keith’s shoulders slackened, and he bowed his head, and suddenly the fear left him. Shiro lifted Keith’s jaw, felt the fevered skin of his cheek under his hand.

“You were the only thing that kept me going,” said Shiro, and it sounded trite but it was true, all of it, and he couldn’t stop when they were closer than they’d ever been. “When I couldn’t remember my name, or what I looked like, I remembered you.”

“But–”

“You were the one I came home for.” He paused. “If that’s out of line, I’m sorry. We can forget this ever happened.”

“No,” said Keith, forceful and immediate. “No. It’s… it’s insane, but I left the Garrison because you weren’t there. When you left, it’s like everything I wanted left with you. Even if this is some sort of fucked up Galra thing, that hasn’t changed.”

“We’ll talk more when you’re better,” said Shiro. “This could be the fever talking – it might be best if you tried to get some sleep.”

“No, _no_. Shiro, you don’t say shit like that and then talk like it didn’t happen. When Lance tried to touch me I almost bit him, so it’s not like I’ll jump on anything that comes along. Whatever’s going on with me right now, it wants you." 

Shiro stared at him. Keith stared back, defiant.

“Fine,” said Shiro, and the word was like a release switch – the past three years suddenly released like a satellite launched and swinging out into space. “What do you want?”

And that could have sounded petulant but Shiro made it sound like the most heartfelt, important question he would ever ask, like he wanted to please Keith –and Shiro loved him. 

“I want you,” said Keith roughly. His skin flushed deep with purple, heat and caramel scent rising between them, and he swallowed. “And don’t try to tell me I’m sick or that my judgement’s impaired. I know what I want." 

“Okay,” said Shiro. And then he lifted Keith’s jaw gently in his palm and kissed him.

It felt, deeply and truly, like coming home to something he never knew he’d left. Keith moved into him like he’d always been there, been there his entire life and only briefly been away – the heat sparked like static, and Keith’s mouth tasted hot and sweet with something unfamiliar, but Keith fit in his hands like he’d been born to fit them.

Shiro broke the kiss first. The other boy made a small noise into his mouth, but he didn’t move far: just far enough to see Keith, to look into his eyes and ask silently whether it was the same for both of them. Keith’s lips had the beginnings of bruising.

“We waited this long,” said Keith, amazed, and then seemed to have no more words to say.

They moved together, Shiro pressing forward and Keith gasping into his mouth, moving back onto the bed and Keith was suddenly on top of him. He squirmed down into Shiro’s lap and they were grasping at the skin beneath their shirts, Shiro sliding his hand up Keith’s back – stretched out, he could almost span the width of Keith’s back with finger and thumb – then pulling his shirt over his head.

“Shiro,” said Keith, just to say his name, and Shiro took in the sight of Keith’s bare chest, leanly muscled and pale. The scent glands at his throat were sharp and burning red. “Shiro, can’t you just-”

It was all the permission Shiro needed to bury his nose and mouth in the hollow of Keith’s throat. Keith’s head fell back, just as it had out in the corridor, and he whined low in his throat for Shiro. When Shiro applied his teeth, he went wild, shameless and moaning and clutching at Shiro’s hair, pushing him further into his neck – then, Shiro bit.

Keith howled. The sound was loud and primal – Shiro felt himself grow hard, but even that was secondary – and slick suddenly filled Shiro’s mouth. When he pulled away, the bite had sunk cleanly into Keith’s skin.

“I’m sorry,” said Shiro, but Keith had drawn him into a greedy kiss and the words were mostly lost.

It was probably better, he thought dazedly, as Keith began to kiss and lick his way down Shiro’s chest. He could do simple, and they were both running on instinct: this was about where Shiro had stopped his other partners, guys in his classes or previous girlfriends, because it had never seemed right. He must have been waiting for this, for Keith’s slim hands and fingers undoing the button on his pants and tugging them roughly off, for Keith’s bruised, pretty mouth on his cock.

“Keith,” he said, clutching at the boy’s hair as he swallowed Shiro down, “That’s good, you’re so good.”

Keith hummed, and released another wave of incredible scent that made Shiro feel like he was drunk with it. Keith was clumsy, unsure where to put his hands, but it didn’t matter. It was Keith, and Shiro loved him.

“Thought about this,” said Shiro, and Keith looked up. The head of Shiro’s dick popped from his mouth and a line of spit was tracking its way down his lip. Shiro couldn’t help but smile.

“This better be okay,” Keith said warningly. “It’s harder than it looks.”

Shiro cupped his warm face and said, “You’re perfect. Keep going.”

“Hold on,” said Keith. Then he moved onto his knees and tugged his own pants off with minimal fuss.

“Wait,” said Shiro, “Come up here.”

Keith looked confused for a few moments. Then he realised what Shiro wanted, and his face grew somehow redder. Slowly, he crawled up to where the other man lay, awkwardly presenting himself to Shiro.

When Keith put his mouth to use on Shiro’s dick, he did so more forcefully than he had before. He had to arch his back to reach. The curve of it was incredible, the sight of Keith’s ass as Shiro slowly drew his briefs down his thighs, the way Keith shivered as Shiro’s nails grazed the skin there.

He moaned around Shiro as the older man palmed his ass. The tone of muscle was barely there, and Keith’s ass was soft in Shiro’s hands. His hole twitched when Shiro brushed a slick thumb across it. When Shiro pushed in, Keith moaned and shuddered. Shiro’s dick fell from his mouth, but he made no move to put it back.

“You’ve been playing with yourself,” said Shiro, feeling Keith grasp at his thighs and then the sheets.

“Yeah,” said Keith, “Yeah, I have.” Then his asshole clenched tight around Shiro’s thumb and Shiro laughed, breathily. 

“When do you find the time?” he said, and Keith exhaled shakily against his thigh.

“When everyone goes for training,” he said, and Shiro pushed in deeper. “I use the training room first, and then-”

“Then?”

Keith doesn’t answer, and Shiro draws his thumb out, watching him clench on air. “Then what, Keith?”

“Then I take a shower, and then I go back to my room and fuck myself.”

Shiro chuckled. Keith was so impossibly blunt, even now. His legs shook where they straddled Shiro’s lap. “How do you like it?”

“Ah,” said Keith. Then Shiro pushed in two, large fingers and Keith was moaning. “I can’t get lube, so it’s hard if I don’t have much time, but I can use two, maybe three. I can’t get that deep, not as deep as you are.”

Shiro pressed his fingers down, and Keith’s breath hitched. “Yeah,” he said, “There. God, please!”

When Shiro slammed his fingers there, the boy swore and shuddered, pushing back into Shiro. “More,” he said, “more, Shiro,” and Shiro wasn’t cruel enough to hold out on him.

“Keith,” he said suddenly, and drew his fingers out. Keith was clean. When Shiro spread his fingers, the cloudy slick he’d felt spread with them. “Don’t panic, but you’re making some sort of…”

“Oh,” said Keith, calmly, “yeah, that always happens. I didn’t think it was a big deal.” And he took Shiro’s cock back into his mouth. When Shiro’s tongue pressed inside him, he briefly lost the ability to think.

“You get wet,” said Shiro, roughly. “You get wet when I’m fucking you.”

Keith canted his hips back; Shiro’s voice was making him lose his mind, slipping into a growl that went through his entire body. Having Shiro was something he’d thought about many times but never seriously, after he’d left the Garrison, but now Shiro was here with him and having sex with him. The Keith of three years ago would never have believed it.

“You’re so good, so hot,” Shiro was saying, and somehow he’d made it up to three fingers and was still stretching him wider.

“Fuck me,” said Keith, and it was more of a whine than an order. His jaw was hurting and he’d done enough waiting, three years of it, two of them spent alone. “I want to feel you in me.”

Shiro groaned, and Keith knew he had him. He grinned into the sheets and said, in the smallest voice he could manage, “Where do you want me?”

The question made Shiro pause, and then Keith was on his back, the world suddenly flipped and he realised with a rush of arousal that Shiro had manhandled him, had his hands on him and was lifting Keith on top of him as if Keith weighed nothing.

“Fuck,” Keith breathed, and then Shiro was lining his cock up with Keith’s hole and pressing in.

The stretch burned. Shiro’s dick was proportionate, thick and hot as it filled him, and Keith’s heart stuck in his throat as gravity pulled him downwards into Shiro. He’d made out that it was normal, but Keith only produced slick when he was aroused, and he was more aroused than he’d ever been in his life. He could feel himself clenching, hot and wet, around Shiro’s cock. 

“You okay?” Shiro asked, and it was so typical of him to ask him that when he was filling Keith so good. Keith breathed out some response, but he could barely breathe, legs shaking so hard he could barely hold himself upright – then he realised Shiro was doing that for him, too, holding his waist with strong and steady hands.

The heat was burning him. Keith had woken up this morning sweaty and hard, and showering had only made it worse, and he’d tried to masturbate but he couldn’t cum. Everything in him had told him to get out of bed and look for Shiro, because Shiro would help, Shiro was his and he had to and Shiro would want him and hold him and fuck him – it was a half-assed plan, and Keith had slowly come back to himself when he’d found the man. The rational side of Keith’s brain told him that he’d wanted Shiro for ages, Galran or not.

Shiro wasn’t Galran. That didn’t matter when he could fuck Keith like one, as good, as hard, and would be just as strong as any Galran Keith could mate.

Keith shifted experimentally, and Shiro seemed to take that as an invitation. Grip tightening, Keith was unceremoniously tugged down impossibly further. Shiro began to fuck Keith down onto his cock, hips moving into each downstroke, as if Keith was a toy being used only to pleasure him. The thought of existing to pleasure Shiro, of being Shiro’s to use as he liked, only turned him on more.

Soon, Keith was letting out sharp little cries as Shiro fucked him. The other man’s eyes were intent, his teeth were clenched, and Keith flushed as he realised Shiro was watching the place where his cock disappeared inside Keith’s ass.

“So good,” said Shiro again, and then he said, “ _Made for this_ ,” and Keith’s heart nearly stopped.

“What?” he choked out, but Shiro didn’t need to be told.

“I knew you were made for me to fuck,” he said – and Keith could see the tips of his ears turning red, but even that wasn’t enough to break the spell Shiro had him under. “I thought about fucking you, back on Earth, then here.”

“When we were training?” Keith breathed.

“I asked,” said Shiro, and the next drop made Keith see white, “to train you,” again, and breath hitched, “so I could fuck you on the gym mats. I could say I was training you, and no one would question why I was pulling you out of class so often.”

Even Shiro had his limits: he let Keith down slowly, let him sprawl across his chest so Shiro could fuck into him at a cleaner angle.

“I wanted you to,” said Keith, and felt Shiro shudder against him. “I wanted you to fuck me back then. Everyone said you were the best, talked about how strong you were. You could’ve held me down and fucked me then. I wouldn’t have minded.”

Shiro grunted. “You were young, Keith, and small for your age. I didn’t want to hurt you."

“You can,” Keith said, and bit down hard on Shiro’s clavicle. “Be rough, I mean. I won’t break on you.”

“You’re right,” said Shiro. And then Shiro brought his left hand to rest on Keith’s ass, felt Keith squirm into it. He lifted his palm and brought it down in a hard slap, and Keith cried out.

“Fuck, Shiro, please-"

Shiro spanked him twice, a third time, four five six seven, and when he spoke his voice was rough in Keith’s ear. “Omega,” he said, “You were built for me to fuck.”

Keith’s world shattered and flared black. He was coming, blindingly hard, and Shiro continued to fuck into him as he came – small shocks raced through his veins with each new thrust. He was making panicky little noises against Shiro’s chest. Shiro’s hands were gentle on Keith’s back as he finished, pulling out just as he came.

He could feel Shiro’s seed on his ass, and that was vaguely disgusting but overwhelmingly hot. Keith’s own cum was drying sticky between them, but he was content to stay there for a while.

Shiro’s lips pressed into his hair. His arms were secure, and Keith’s scattered thoughts came back to him as Shiro held him there.

He didn’t register that Shiro was speaking to him until several minutes had gone by. His breathing was even, calming him, and he seemed to be telling stories from his time in the academy. None of them were particularly interesting, but it was just what Keith needed to hear.

The heat was slowly fading, and Kieth felt almost normal again. The stretch Shiro had left behind was irritating, rather than painful. The hands rubbing across Keith’s back were soothing. 

“Thanks,” he said. 

Shiro paused. “You don’t have to thank me,” he said.

“Thank you,” said Keith, stubborn, and raised himself up on his hands to look at Shiro. “Just take the gratitude and live with it.”

Shiro’s eyes softened. “Okay.”

 

 

**Author's Note:**

> *launches headfirst into fandom* 
> 
> for more sheith feels/Keith's emo playlists ---> http://8tracks.com/eyesinmine/in-this-castle


End file.
